Sodium hydroxide-containing solids, also referred to as caustic soda, are difficult to handle because they are very hazardous when contacted with unprotected skin. Sodium hydroxide can cause severe burns with deep ulcerations and permanent scarring resulting.
Many detergents such as automatic dishwashing detergents, soaps, and drain cleaners include sodium hydroxide (caustic soda) as a component. While sodium hydroxide is an effective cleaning agent it can also pose serious health concerns when contacted with skin.
Solid or powdered sodium hydroxide is also very hygroscopic. That is, it attracts and absorbs water or humidity from the atmosphere. In humid environments such as the tropics or even many locations during the summer, sodium hydroxide-containing solids are difficult to store because they absorb water from the atmosphere. This means that powdered solids often turn into pastes or gooey agglomerates making them impossible or difficult to dispense.
In order to protect the end-user from the corrosivity of sodium hydroxide, one option is to package the caustic-containing solid in packaging such that contact with skin cannot occur. Different packages have been used. These packages include a water-soluble polymer that dissolves upon contact with water. The end-user places the polymer-encased solid in the dispenser and when exposed to water the polymer dissolves thereby exposing the encased solid for use. A drawback of polymer encasement is the expense. Another option is to encase the solid in a plastic container. However, removing the plastic may result in contact of the solid with skin. Both of the encasement options help to reduce water absorption from the atmosphere. Another option for avoiding caustic burns is for the end-user to use some sort of skin-protectant such as gloves. Gloves work well to protect the end-user except the user is not always compliant and skin contact with the caustic can result. Gloves are also not a suitable option for eliminating water absorption from the atmosphere in humid environments.
Another option for protecting the end-user from the caustic in detergents and for reducing water absorption from the atmosphere is desirable. A protectant that is inexpensive, easy to form and effective at protecting the end-user from burns and protects the caustic from humidity is sought.